KP 250 Crossover suggestions

[Pete H]

I'm selling one set of the KP250's to a friend and want to freshen up the networks for him.  These are not going to be used for PA application and will actually be used in his "studio cave" for his personal listening, vocals, keyboards etc. and he's not going to pump stupid amounts of power through them either.  Anyway, got me thinking that the protection built into the networks is unnecessary and the network itself, probably isn't the best for what these are going to be used for, but with so many variations on the heresy and the many iterations of pro and industrial, can any of you that have experience, guide me in the proper direction to get the best sound out of them by putting in the proper network for the described application?

 

Stock components but diaphragms for the tweeters have been replaced with Crites titanium. 

 

Thanks in advance!

[glens]

I'd be inclined to leave them as-is unless just maybe freshen the capacitors if you don't think they sound like they should.  The protection is okay to leave in and in all respects the crossover design is proper for the speaker - if it's original.

[rockhound]

@mark1101 just did some mods to his HSM's maybe he has some thoughts?

[Pete H]

41 minutes ago, glens said:

I'd be inclined to leave them as-is unless just maybe freshen the capacitors if you don't think they sound like they should.  The protection is okay to leave in and in all respects the crossover design is proper for the speaker - if it's original.

I appreciate the thought, but if performance (sound quality) has been reduced by the design in order to protect the components first and foremost, that is the whole point in my question.  

16 minutes ago, rockhound said:

ark1101 just did some mods to his HSM's maybe he has some thoughts?

Hopefully he will chime in.  Did he have a thread about it?  I'll take a look and maybe send him a PM.  I would expect to get a lot of other responses based on the number of Heresy's/Industrial and KP's that are out there as well as this groups obsession with better and experimentation. 

[glens]

The protection, on the tweeter only, is merely a thermal switch in parallel with a resistor which maintains a load behind the crossover parts to protect the amp if/when the switch opens (and the tweeter didn't blow).  I suppose it's possible the switch is adding a small part of an ohm, but if the tweeter is 8 ohms and the switch is (it's not) at 1 ohm, that'd only a 1dB reductIon in output.

 

2 hours ago, Pete H said:

if performance (sound quality) has been reduced by the design in order to protect the components first and foremost, that is the whole point in my question.

 

No reduction in sound quality to afford protection.  Some folks may say there's a difference but there are also some folks that hear difference in power cords, speaker wire alloy, capacitor orientation, etc.  It's a non-issue, most certainly, in this case.  A larger issue would be the woofer which may be designed for less lower-bass to trade for increased output.  The balance of the sound with those speakers is as good as it can be when the stock crossovers are used.  So long as the capacitors are within spec.

[Pete H]

18 minutes ago, glens said:

No reduction in sound quality to afford protection.  Some folks may say there's a difference but there are also some folks that hear difference in power cords, speaker wire alloy, capacitor orientation, etc.

I don't subscribe to any of the snake oil, but knowing the vast number of crossovers that have been used across the Heresy/Pro/Industrial/and modified versions, and looking at the KP250/B network that's in them, would lead me to think (not being any kind of expert on the subject), that there would be better networks for the specific application that I referenced.  I also would like to provide a network that will allow the drivers to function as efficiently and accurately as they're capable of within the ported cabinet they reside.  Claude has done and many others have followed with Super Heresy's 1's and 2's and other iterations and I'm quite certain that none of those have been done using a network that is anything like this one.  Hey, I could be wrong, but not based on what I've seen, which is why I'm hoping that other people having done things like this, can direct or correct me as needed.  

Edited May 4, 2019 by Pete H
finish a statement

[ClaudeJ1]

I would replace the Electrolytic capacitor, then look to see if the ESR is low on the others, or just replace them, since it's cheaper than buying an ESR meter. I ran curves on my KP-250's used for R and L side channels in my HT, and they are just fine. I also tried to insert some longer ports in the 2 port holes in an attempt to lower the bass, but it was not worth the effort, so I put it back to stock. The inductors should be fine.

[jimjimbo]

Pete, I don't see anything inherently wrong with the networks as they are, other than looking a mess....lol.  Agree with Claude on his points.

[Pete H]

13 hours ago, ClaudeJ1 said:

I would replace the Electrolytic capacitor, then look to see if the ESR is low on the others, or just replace them, since it's cheaper than buying an EST meter. I ran curves on my KP-250's used for R and L side channels in my HT, and they are just fine. I also tried to insert some longer ports in the 2 port holes in an attempt to lower the bass, but it was not worth the effort, so I put it back to stock. The inductors should be fine.

I have a kit from Bob to freshen up the network as is and I'm glad to hear that you have already tried to improve on them although I'm really shocked that network that was designed for PA application is optimized for superior normal listening levels in small rooms.  But that is why I'm asking those of you that know, I do not and am not going to reinvent the wheel.

3 hours ago, jimjimbo said:

Pete, I don't see anything inherently wrong with the networks as they are, other than looking a mess....lol.  Agree with Claude on his points.

Mess, is exactly what I thought when I pulled out the networks in the 250's and the 115's (they make the 250 networks look clean)  I will see if I can make things look a bit better when I get all the new parts laid out for replacement.  It really sucks when you don't get the answer you were hoping for, but that's better than me going off and doing something that wouldn't work properly.

[mark1101]

19 hours ago, rockhound said:

@mark1101 just did some mods to his HSM's maybe he has some thoughts?

 

Well, what I did was convert Heresy stage monitors to home Heresys.  Not the same thing you have here.  But when I look at these networks I would not be happy with electrolytics and all that tweeter protection.  I removed fuses and tweeter protection (Zeners) in just about all the Klipsch I ever owned.  I have never blown a driver either in 40+ years.  Basically for the small Klipsch like this I always preferred the simpler home networks.

[jimjimbo]

1 hour ago, Pete H said:

I have a kit from Bob to freshen up the network as is and I'm glad to hear that you have already tried to improve on them although I'm really shocked that network that was designed for PA application is optimized for superior normal listening levels in small rooms.  But that is why I'm asking those of you that know, I do not and am not going to reinvent the wheel.

Mess, is exactly what I thought when I pulled out the networks in the 250's and the 115's (they make the 250 networks look clean)  I will see if I can make things look a bit better when I get all the new parts laid out for replacement.  It really sucks when you don't get the answer you were hoping for, but that's better than me going off and doing something that wouldn't work properly.

Pete,  perhaps this is the simple answer you were looking for......As Mark did with his HSMs, replace the networks with E networks.  No zeners, simple design.  Not sure if you want to replace the heavy duty woofers as well, but that's a thought.  At the low/modest listening levels you described, this should be a decent compromise.

[glens]

No diodes in this network, and like I said, the network is proper for the drivers.  If one changes the network they'll need to change the drivers and vice versa.  It is what it is and except for maybe the caps is the best it can be without "re-inventing the wheel."

 

If a person thought they'd never pour coals to the fire and thought the thermal switch (basically a self-resetting fuse) detracted from the signal going to the tweeter, then it'd be a simple matter to short the switch/resistor pair with a clip-on jumper and see if it changes the sound any whatsoever, making it permanent if desired.  Personally, it'd be a waste of time.

[ClaudeJ1]

2 hours ago, Pete H said:

I have a kit from Bob to freshen up the network as is and I'm glad to hear that you have already tried to improve on them although I'm really shocked that network that was designed for PA application is optimized for superior normal listening levels in small rooms.  But that is why I'm asking those of you that know, I do not and am not going to reinvent the wheel.

Mess, is exactly what I thought when I pulled out the networks in the 250's and the 115's (they make the 250 networks look clean)  I will see if I can make things look a bit better when I get all the new parts laid out for replacement.  It really sucks when you don't get the answer you were hoping for, but that's better than me going off and doing something that wouldn't work properly.

I didn't say it was optimized for normal listening, I just said that I'm using it for surround channels. Between my Jubilee's with TADs and Danley sh-50's with top of the line Tapped Horn subs, my "normal listening" is way beyond modified little boxes. But if I were to use them as such, Sub woofers would be called for, as I said previously. Even actual Super Heresy's sound better with a coffee table sub!!

[ClaudeJ1]

39 minutes ago, jimjimbo said:

Pete,  perhaps this is the simple answer you were looking for......As Mark did with his HSMs, replace the networks with E networks.  No zeners, simple design.  Not sure if you want to replace the heavy duty woofers as well, but that's a thought.  At the low/modest listening levels you described, this should be a decent compromise.

If you go the replacement route, E-2 Networks might be better.

[ClaudeJ1]

18 hours ago, Pete H said:

Good Afternoon!

 

I was again, reading through your work on the Super Heresy and SH2 and I'm in the process of redoing 2 sets of KP250's, one which I'm selling to a friend and with all of your knowledge and work on the Heresy's I thought you might be the best person to ask with regards to making the KP's better.  I've replace the tweeter diaphragms with Crites titaniums and that was a big improvement, but anything you could offer would be greatly appreciated.  These are not being used, nor will be used in a PA environment at all, not will they have crazy power thrown at them so I'm looking to get the networks/drivers/ports dialed in as to best reproduce music in reasonably sized rooms.  I know you're a busy man, so if you find the opportunity to answer, I thank you in advance.

 

Pete

I'm currently using a pair for my L and R side channels. There's not a whole lot you can do to improve them. They have a K42 woofer already and ports are optimized for that box. I tried using deeper ports in front and found they were not worth it.

 

However, If you were to seal the 2 front ports and install the single rear firing port I used on the SH's, you might get improved bass below 80 Hz. but it may not be worth the trouble unless you can move them into corner and/or slightly away from flat walls like the I had them 5 years ago, before I sold them to JimJimbo. And even then, I can't gurantee it like I have the SH mods, since I never did that myself and measured.  That speaker is already pretty good the way it is, and, along with the rear porting, you would have to change the crossover to an E2. There's a reason why I chose to use the Heresy 1 for a mod, since it's so old and give the most improvement of all the mods (especially Version 2.0 with DaveA's tweeter lens vs. a 50 year old K-77. Since you have a good tweeter in there already, I don't think it would improve much. Mine are stock and the tweeters are excellent as it.

 

Again, it may not be worth it to rear port and stuff the enclosure while changing the network, and you'd be better off getting them on top of 2 12" sub woofers crossed at 80 Hz. That's what I would do. Besides, the SH mod is true and tested by so many people, but ONLY for specific boxes, namely Heresy 1 and 1.5. All others are not tested or done by me. OK?

 

PS: Pete H, yes I know it really sucks when you don't get the answer you were hoping for, but I will NOT propose theories about things I have not done and measured myself with exact conditions described. I don't want to waste anyone's time or money "chasing the voodoo" (Miles Davis title). Ideally I would like world peace, a million $/month retirement, and an end to poverty and hunger. But that ain't gonna happen.

[Pete H]

1 hour ago, glens said:

No diodes in this network, and like I said, the network is proper for the drivers.  If one changes the network they'll need to change the drivers and vice versa.  It is what it is and except for maybe the caps is the best it can be without "re-inventing the wheel."

Noted and thank you and the rest that have commented.  I'm just going to recap what's there based on everything that's been said.  

27 minutes ago, ClaudeJ1 said:

PS: Pete H, yes I know it really sucks when you don't get the answer you were hoping for, but I will NOT propose theories about things I have not done and measured myself with exact conditions described. I don't want to waste anyone's time or money "chasing the voodoo" (Miles Davis title). Ideally I would like world peace, a million $/month retirement, and an end to poverty and hunger. But that ain't gonna happen.

I absolutely understand, which is why I do value those opinions that are based on knowledge that I don't possess.  I have the same conversations with clients, where I am the expert and many times, I'm the one that has to tell them the way it is, versus what they want to hear.  Thanks again, it it appreciated

 

I'll have one final question regarding the fuse's on the input cup, but I want to post a picture. 

[Pete H]

2 questions:

Fuse caps disintegrated when I removed them and back when I looked, it wasn't something that I could easily find.  Any problem just bypassing the fuse altogether or any clue where I can get new caps?  

Terminal plate on the K42 is broken off and crazy glue obviously wasn't the solution.  JB weld?  I've never had this happen on a driver so if any of you have, I'm all ears.

 

[ClaudeJ1]

The woofer shown is by Eminence, the same one I recommend for the Super Heresy 1.0. No problem shorting the fuse for home use.

[glens]

JB Weld may work well.

[Pete H]

1 hour ago, glens said:

JB Weld may work well.

It's next on the list.